Reversible multi-stage hydraulic machine

ABSTRACT

A reversible multi-stage hydraulic machine having a minimum of three stages where the wheels are disposed on a common shaft; one of the wheels is disposed with its suction aperture directed on the opposite side to the suction apertures of the wheels of the other stages and is arranged back to back to its adjacent wheel; jointly and simultaneously regulable distributors are arranged each on the periphery of the wheels arranged each other back to back; a set of obturators in the machine makes it possible for at least one stage to be put out of action.

tlnited States Patent [191 Faueonnet Feb. 1 8, 1975 4/1944 Staples.............

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Switzerland Primary Examiner-C. J. Husar [22] Filed: Oct. 29, 1973 Assistant ExaminerL. J. Casaregola Attorney, Agent or Firm-Robert A. Ostmann Appl. N0.: 410,898

[57] ABSTRACT stage hydraulic machine having a [30] Foreign Application Priority Data A ibl mminimum of three stages where the wheels are disposed on a common shaft; one of the wheels is dis- Oct. 31, 1973 Switzerland............ .4 15846/73 415/153, 415/500 posed with its suction aperture directed on the opposite side to the suction apertures of the wheels of the other stages and is arranged back to back to its adjacent wheel; jointly and simultaneously regulable distributors are arranged each on the periphery of the wheels arranged each other back to back; a set of ob- [51] Int. CLFOld 13/02, FOld 1/30, F01d 1/00 [58] Field of Search [56] References Cited turators in the machine makes it possible for at least UNITED STATES PATENTS one stage to be put out of action.

245,590 3/1884 415/166 5 Claims, 4 Drawing Figures PATENTEDFEB'I I 3.867, 059

. SHEET 2 OF 2 REVERSIBLE MULTI-STAGE HYDRAULIC MAC HINlE BACKGROUND OF THE INVENTION The present invention relates to a reversible hydraulic machine having a minimum of three stages, and so designed as to be able to put one or more stages out of service at will, the wheels in the said machine being disposed on the common shaft.

In general, reversible hydraulic machines coupled to an alternator-motor and rotating at the same angular velocity in both directions of rotation reach their conditions of maximum efficency as turbines with heads which are from to 40 percent greater than the elevation heights obtained under maximum efficency conditions during pumping; consequently, a reversible single-stage hydraulic machine cannot generally be so dimensioned as to operate as a turbine in the head range corresponding to its optimum efficiency. This results in a regrettable loss of energy which often justifies having recourse to ternary or isogyre solutions these utilising two wheels with different traces and situated each on separate passage of flow for conditions of operation as a turbine or as a pump.

When the high heads make it necessary to utilise a multi-stage machine, it becomes possible to overcome this disadvantage by a constructional design making it possible to put a larger number of stages into operation for working as a pump than for working as a turbine. Judicious selection of the individual blading traces of the various wheels then makes it possible to adapt the machine to installation conditions, so that it operates close to optimum efficiency, both as a turbine and as a pump.

Wheels required to operate under turbine conditions are preferably fed by means of a directable distributor. Under any head this device makes it possible to adjust the flow while retaining the highest possible efficiency. A simplification consists in providing distributors only for some of the wheels during turbine operation. However, the distribution of the head over the stages is hereby unbalanced, which is detrimental to efficiency and makes it necessary to limit the range of adjustment.

SUMMARY OF THE INVENTION The object of the present invention is to achieve greater efficiency in reversible multi-stage hydraulic machines initially described, accompanied by better distribution of the head over the under turbine conditions required stages.

According to the present invention, this object is achieved in the case of a reversible multi-stage hydraulic machine comprising at least three stages in which the wheels are disposed on a common shaft by disposing at least one of the wheels with its suction aperture directed on the opposite side to the suction apertures of the wheels of the other stages and by arranging this wheel back to back to the wheel in the adjacent stage, further by disposing a set of obturators in the machine for putting at least one of the stages out of action, and more further by arranging each one regulable distributor in the two adjacent stages in which said wheel are arranged each other back to back and the distributors being regulable jointly and simultaneously.

According to the present invention at least one of the set of obturators for putting at least one stage out of action is of the cylindrical type commonly known as a sleeve valve.

It is advantageous if one of the obturators is a doubleaction sleeve valve.

As one of the obturators a double-action rotary obturator too is shown in one of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWING The accompanying drawings illustrate diagrammatically and by way of example one form of construction of the machine according to the invention, and also a variant.

FIG. 1 is a view thereof in longitudinal section, whereby on the left the machine being adjusted for the pumpand on the right for the turbine operating is shown.

FIG. 2 is a view thereof in cross-section on the line Il-Il in FIG. 1.

FIG. 3 is a view in longitudinal section, similar to- FIG. 1, of the variant, showing a machine equipped with a set of different obturators, whereby on the left the machine being adjusted for the pumpand on the right for the turbine operating is shown.

FIG. 4 is a view thereof in cross-section on the line IVlV in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The machine shown in FIG. 1 and 2 comprises a shaft 1 which is carried by bearings (not shown) and on which are disposed three wheels numbered 2, 3 and 4; the suction aperture of the wheel 2 is directed on the opposite side to the suction apertures of the wheels 3 and 4 (its blading is arranged accordingly) and this wheel 2 is arranged back to back to the wheel 4 which is in the adjacent stage relatively to the wheel 2.

Two distributors 5 and 6, each of which is formed of a series of movable blades, are each one disposed on the periphery of the wheels 4 and 2 respectively. These last two wheels 4 and 2 have their suction apertures in opposition, so that the distributors 5 and 6 are relatively very closely adjacent. Shafts 7 each carry a guide blade of the distributor 5 and a guide blade of the distributor 6. Connecting rods 8 mounted on the shafts 7 and driven in known manner by the single and common regulating ring 9 permits simultaneous adjustment of the angular position of all the blades of the distributors 5 and 6, thus effecting simultaneous adjustment of the admission of water to the wheels 4 and 2 of the machine and a balanced distribution of the head over the wheels 4 and 2.

Ducts 10 and 11 situated beyond the distributors 5 and 6, in relation to the wheels 4 and 2, are formed in such a manner as to lead to a crossing part 12. This part, of known shape, enables the ducts 10 to lead to a spiral casing 13 by way of a path 12a, while the ducts 11 pass through apertures 12b in the part 12, these apertures bringing them into communication with the remainder of the machine.

Beyond the apertures 12b, these ducts are divided into two branches 14 and 15. The branch 14 rejoins the suction aperture of the wheel 3. The branch 15 is directed towards the suction aperture of the wheel 4 to which it leads through a duct 16 after passing the junction of a return duct 17 of the wheel 3.

The ducts 14 and 15 can be alternately closed by an obturator 18 shown in FIG. 1 in the form of a double action sleeve valve. Another sleeve valve 19 disposed on the periphery of the wheel 3 can at will close the return duct 17.

Taking these arrangements into account, the machine is designed to operate as a turbine with the two stages corresponding to the wheels 4 and 2 only, and to operate as a pump with the three stages on action.

During operation as a turbine, the valves 18 and 19 are situated in the positions shown in the right part of FIG. 1, bearing the references 18a and 19a. The wheel 3 is then put out of action and emptied by a usual type of device (not shown) in order to avoid a loss of energy through splashing.

After the opening of a check valve (not shown), the water under pressure enters the spiral casing 13. The water then flows into the ducts 12a, 10, passes through the distributor 5, which has been opened to the desired position to feed the wheel 4. After escaping from the suction aperture of the latter, the water is guided through the successive duct elements 16, 15, 12b, and 11, to the distributor 6 which feeds the wheel 2. After passing through the latter, the water escapes from the machine through the suction tube 20. The wheel 2, which is assumed to have the same arrangement as the wheel 4 (except for the direction of rotation), being fed by a distributor 6 located under the same driving means, namely the single and common regulating ring 9, as the distributor 5, this results in a conversion of energy which is also distributed over the two wheels and the range of adjustment will be as wide as that is normally possible with a single-stage Francis turbine.

For operation as a pump the machine is driven in the opposite direction of rotation to that for turbine operation. The valves 18 and 19 are in the positions shown in the left part of FIG. 1. The wheel 3 is then inserted into the water circuit and must previously be refilled either before the pump is put into operation or at least during the opening of the (not shown) check valve isolating the machine from the (not shown) penstock. The two distributors 5 and 6 are kept in a predetermined open position, defined in dependance on the delivery head.

The water drawn in by the wheel 2 is successively passed to the wheel 3 and then to the wheel 4 through ducts for which the free passage is determined by the valves and attains a delivery head enabling it to escape through the spiral casing 13 in the direction of the delivery pipe of the pump-turbine plant.

The trace of the wheel 3 is generally different from that of the wheels 2 and 4. The portions of the delivery head treated by the wheels 2 and 4 are equal, and that treated by the wheel 3 supplies the make-up ensuring operation with optimum efficiency, taking into account the range of variation of the upstream and downstream pond levels of the pump-turbine plant.

In the variant illustrated in FIGS. 3 and 4 the sleeve valve 18 is replaced by a rotary obturator 21 composed of a ring provided alternately with apertures 22 having a bent passage and apertures 23 having a direct passage. An operating device (not shown) makes it possible to turn the obturator one step in one direction or 6 It is seen that if the apertures 22 are fed by the ducts 12b, the conditions supplied by the sleeve valve in the position 18a in FIG. 1 are once again exactly obtained, the ducts 15 are fed while the ducts 14 are obturated, and the machine is ready for operation as a turbine, provided that the sleeve valve 19a is closed as previously.

If the apertures 23 are fed by the ducts 12b, the situation corresponding to the position 18 in FIG. 1 of the sleeve valve is found once again, the ducts 14 are fed and the ducts 15 are closed; the machine is ready to operate as a pump, provided that the sleeve valve 19 is opened as previously.

Numerous other modifications of the embodiment described and illustrated in the drawing can be contemplated.

In particular, stages may be added on either side of the set of wheels 3, 4, 2, the wheel or wheels added at the side of the wheel 3 having its or their suction apertures directed in the same direction as those of the wheels 3 and 4, while the wheels added at the side of the wheel 2 have their suction apertures directed in the same direction as those of the latter.

Obviously, particularly in the case of machines having a large number of stages, it is possible to provide obturators enabling a group of a plurality of stages to be put out of action.

The arrrangement of the wheels of the hydraulic machines described above permits a substantial simplification of the simulataneous operation of two distributors 5 and 6 placed on two contiguous stages in which the wheels 2 and 4 have their suction apertures in position and are arranged each other back to back. Furthermore, they make it possible to put out of action a stage or group of stages with the aid of obturators of various kinds incorporated in the machine.

Finally, the fact that one or more wheels of the machine are situated with their suction apertures directed in opposite directions make it possible to reduce the axial thrusts and the differences in pressure at the joints, thus improving efficiency.

I claim:

1. A reversible hydraulic machine including a. a pump-turbine part having at least two stages, and

a pump part having at least one stage,

b. each stage including an impeller,'and the impellers being coupled to a common shaft,

0. the impellers of said two stages of the pumpturbine part being arranged in juxtaposition and back-to-back with their suction apertures facing in opposite directions;

d. two sets of distributors with adjustable stator blades, one being associated with each of said two stages of the pump-turbine part;

e. common regulating means for simultaneously adjusting the setting of both sets of blades; and

f. passage means interconnecting the stages and containing obturator means for selectively putting out of action the pump part,

g. the obturator means having a first setting in which it causes water being pumped to flow from a suction tube to a spiral casing of the machine through a path which leads serially through one stage of the pump-turbine, the pump, and the other stage of the pump-turbine, and a second setting in which it causes water acting as power medium to flow from the spiral casing to the suction tube of the machine through a part which leads serially through said two stages of the pump-turbine part and is isolated from the pump part.

with the second and third passages and opens the second passage. 4. A machine as defined in claim I in which the obturator means includes a rotary valve.

5. A machine as defined in claim 4 in which a. the passage means includes a first passage con nected with the periphery of the first impeller of connects the periphery of one impeller of the pump-turbine part with the suction aperture of the the pump-turbine part, a second passage connected with the suction aperture of the other impeller of other impeller of that part, and second and third 10 the pump-turbine part, and a third passage conpassages which connect the suction aperture and nected with the suction aperture of the impeller of periphery, respectively, of the impeller of the pump the pump part, these passages leading to the rotary part with spaced points along the first passage; and valve; and b. said sleeve valve is of the double-acting type and b. said rotary valve is of the double-acting type and has a first position in which it opens the first pashas two positions in which, respectively, it connects sage and closes the second passage, and a second the first passage with the second and third pasposition in which it closes the first passage at a losages. cation intermediate the junctions of this passage 

1. A reversible hydraulic machine including a. a pump-turbine part having at least two stages, and a pump part having at least one stage, b. each stage including an impeller, and the impellers being coupled to a common shaft, c. the impellers of said two stages of the pump-turbine part being arranged in juxtaposition and back-to-back with their suction apertures facing in opposite directions; d. two sets of distributors with adjustable stator blades, one being associated with each of said two stages of the pumpturbine part; e. common regulating means for simultaneously adjusting the setting of both sets of blades; and f. passage means interconnecting the stages and containing obturator means for selectively putting out of action the pump part, g. the obturator means having a first setting in which it causes water being pumped to flow from a suction tube to a spiral casing of the machine through a path which leads serially through one stage of the pump-turbine, the pump, and the other stage of the pump-turbine, and a second setting in which it causes water acting as power medium to flow from the spiral casing to the suction tube of the machine through a part which leads serially through said two stages of the pump-turbine part and is isolated from the pump part.
 2. A machine as defined in claim 1 in which the obtruator means includes a reciprocable sleeve valve.
 3. A machine as defined in claim 2 in which a. the passage means includes a first passage which connects the periphery of one impeller of the pump-turbine part with the suction aperture of the other impeller of that part, and second and third passages which connect the suction aperture and periphery, respectively, of the impeller of the pump part with spaced points along the first passage; and b. said sleeve valve is of the double-acting type and has a first position in which it opens the first passage and closes the second passage, and a second position in which it closes the first passage at a location intermediate the junctions of this passage with the second and third passages and opens the second passage.
 4. A machine as defined in claim 1 in which the obturator means includes a rotary valve.
 5. A machine as defined in claim 4 in which a. the passage means includes a first passage connected with the periphery of the first impeller of the pump-turbine part, a second passage connected with the suction aperture of the other impeller of the pump-turbine part, and a third passage connected with the suction aperture of the impeller of the pump part, these passages leading to the rotary valve; and b. said rotary valve is of the double-acting type and has two positions in which, respectively, it connects the first passage with the second and third passages. 